Because of changes in local codes and because of the increased expense of installing gravity sewer systems, and also for reasons of ecology, it has become increasingly desirable to employ pressurized sewage handling systems. In many such systems it is desirable to use a basin in which a pump is installed along with its associated electrical and plumbing hardware. The pump can be either a grinder or an effluent type, depending on system requirements.
As will be recognized, provision must be made for removal of the pump for repair or servicing. Thus, it is customary to provide some sort of rather easily disengagable coupling between the pump and the outlet line. It is also necessary to provide some sort of manual shut-off valve which can be closed to prevent back flow when the pump is removed, and a check valve to prevent back flow when the pump is connected but not operating.
Examples of various devices proposed for use in these areas are found in the following patents.
U.S. Pat. Nos. 2,958,547 Batts et al; 3,018,925 Englesson; 3,330,299 Slawinski et al; 3,511,252 Kennedy; 3,592,564 Connery; 3,741,243 Deibler et al; 4,049,234 Spisak; French No. 745,534;